Systemic chemotherapy has become an integral part of primary treatment in patients with both advance and operable breast cancer. The morphological changes occurring in breast tissues have already been described, but the changes in molecular markers and the genetic variations that may occur in these tissues remain to be determine.We will study tissues obtained before and after treatment and evaluate prognostic markers as well as LOH at the p53, BRCA1 and BRCA2- locus. - Breast cancer, chemotherapy effect in tissues., - Human Tissues, Fluids, Cells, etc.